Overhead door assembly

ABSTRACT

An overhead door assembly in which the top edge of the door travels in downwardly opening bow shaped tracks and horizontal transverse pivots on the sides of the door travel in vertical tracks. The top of the door is strengthened and overhangs the bottom which reduces water drip-off and icing at the bottom edge of the door.

111% Dickinson States Patent [191 1 OVERHEAD DOOR ASSEMBLY [76]Inventor: Harold W. Dickinson, Olivia, Minn.

[22] Filed: Aug. 13, 1973 [21] Appl. No.: 387,747

[52] U.S. Cl. 49/197, 49/200 [51] Int. C1 E0511 15/38 [58] Field ofSearch 49/197, 199, 200, 203,

[56] References Cited UNITED STATES PATENTS 1,442,942 1/1923 Gullicksen49/197 X 2,054,191 9/1936 Byrne 49/197 2,718,036 9/1955 Strobel et al.49/200 3,421,260 1/1969 Dickinson 49/200 X Primary Examiner-KennethDowney [5 7 ABSTRACT An overhead door assembly in which the top edge ofthe door travels in downwardly opening bow shaped tracks and horizontaltransverse pivots on the sides of the door travel in vertical tracks.The top of the door is strengthened and overhangs the bottom whichreduces water drip-off and icing at the bottom edge of the door.

3 Claims, 8 Drawing Figures a'.eas;s27

SHEEI 3 0F 4 PATENTED 1974 DOOR PATENTED 8 74 SHEEI E 0? 4 1 OVERHEADDOOR ASSEMBLY FIELD OF THE INVENTION The invention concerns anoverheaddoor assembly of the type in which the top edge of the door rolls inwardon overhead tracks and pivots and slides upward on side tracks.

PRIOR ART The prior art is relatively well developed. Two examples areUS. Pat. Nos. 1,706,442 and 2,l4l,5l5, both of which disclose overheaddoors.

Neither these patents nor others known discuss the problem in coldregions of the collection and freezing of water along the bottom edgesof the door. The door then has to be pried open, a difficult job whichoften results in damage to the door. The top portion of the door of thepresent invention is substantially thicker than the bottom, and theexterior surface of the top portion overhangs that of the bottom by asubstantial amount. Therefore drip-off from the top portion is away fromthe bottom edge of the door, which remains relatively ;dry. In otherwords, the top portion of the door acts as an umbrella for the bottom.However, if a small amount of ice should form along the bottom edge ofthe door, the door may be pried up vertically because it is designed totravel substantially vertically during the first few inches of travelduring opening. Ice is easier to overcome by prying the door verticallyrather than horizontally.

Summary: The invention concerns an overhead door assembly including adoor having a structurally reinforced top portion which is thicker thanthe bottom and overhangs the bottom. Rollers are mounted at the top edgeof the door and travel in arcuate or bow-shaped tracks (sometimes calledprogram tracks or overhead tracks) mounted inside and over the dooropening. The overhead tracks are mounted substantially horizontally andthe bow opens downward. The program tracks control the path of travel ofthe top edge of the door.

The door rotates about pivots mounted in the sides of the door in atransverse axis about which the door is substantially balanced. Thepivots include members which slide in vertical tracks (sometimes calledside tracks or pivot tracks) mounted at the sides of the door opening.As the door is opened, the pivots travel upward and inward in the sidetracks and the door rotates about the pivots. The top portions of theside tracks slope inward and the bottom portions of the side tracks aresupported on the floor and substantially carry the entire weight of thedoor.

The door assembly also includes means for counter balancing the door forease in raising and lowering the door.

In a preferred embodiment the top overhanging portion of the door has acurved outer surface which is stressed for strength. In anotherembodiment the top portion is triangular in cross section. The door maybe built in two sections, an upper and a lower, especially if the dooris relatively large. The two sections can then be assembled at the site.The lower section of the door is bolted to the bottom of the topsection.

The overhead tracks are arcuate or bow-shaped and open downward. Eachtrack has four portions, an outer portion which slopes nearly verticallyupward; a first intermediate portion, adjacent the outer portion, whichslopes upward, but not as steeply as the outer portion; a secondintermediate portion, adjacent the first intermediate portion, which isrelatively horizontal; and an inner portion, adjacent the secondintermediate portion, which slopes downward. The shape of the programtracks accommodates the peculiar contour of the door. As the door swingsand travels inward the upper edge of the door eventually travelsdownward in order to accommodate the thick portion of the door in thehead-space area.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an interior front view ofthe door assembly;

FIG. 2 is a side view of the door assembly;

FIG. 3 is a sectional view of FIG. 1 from the cutting plane 3-3, showingthe construction of a preferred door;

FIG. 4 is a sectional view of FIG. 1 from the cutting plane 4-4, showingthe cable drum;

FIG. 5 is a sectional view of FIG. 1 from the cutting plane 5-5, showinga side track and the position of the door with respect to the wall;

FIG. 6 is a sectional view of FIG. 1 from the cutting plane 6-6, showingthe track and the drum cable within the track;

FIG. 7 is a sectional view of FIG. 1 from the cutting plane 7-7, showinga slide member which is a part of a pivot and how it is positionedwithin a side track; and

FIG. 8 is a sectional view of a door with an upper portion which isgenerally triangular shaped in cross section.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring to FIG. 1, the doorassembly includes a door 10 having an upper section 10a and a lowersection 10b. The top edge of the door is guided by rollers 12a and 12bbolted thereto which roll in overhead tracks 14a and 14b respectively.Tracks 14a and 14b are mounted over the door opening and extendinwardly. Door 10 rotates about pivots 16a and 16b located in the sidesof door 10 near the junction of the top and bottom portions of door 10.Pivots 16a and 16b substantially support the entire weight of door 10.The inner ends of pivots 16a and 16b are journalled in bearings 17a and17b mounted in door 10. The outer ends of pivots 16a and 16b aresecurely attached to slide plates 18a and 18b respectively which slideup and down in side tracks 20a and 20b respectively. Side tracks 20a and20b are also called pivot tracks. Cables 22a and 22b are used to raiseand lower the door. The lower ends of cables 22a and 22b are tied to thetop portions of slide plates 16a and 16b respectively. The upper ends ofcables 22a and 22b pass over cable drums 24a and 24b respectively. Drums24a and 24b are mounted over the door opening on a horizontal shaft 26,called an equalizer shaft. Shaft 26 rotates in bearings 28a and 28blocated just outwardly from cable drums 24a and 24b. The door 10 iscounter balanced by means of pulleys 30a and 30b mounted on equalizershaft 26, ropes 32a and 32b passing over pulleys 30a and 30b, andcounterweights 34a and 34b tied to the lower ends of ropes 32a and 32b.The door is opened by pulling on the lower end of a rope 36 which passesover a pulley 38 mounted on the left end of shaft 26.

The shapes of overhead track 14a and side track 20a are shown moreclearly in FIG. 2. Track 140 is arcuate or bow-shaped with the openingdownward. The slope of the outer end of track 14a, on the left, isnearly vertical for a short distance of several inches. The next portionof track 14a slopes upward to the right. The middle portion of track 14ais practically horizontal and the innermost portion of track 14a slopesdownward. The outermost portion of track 14a is firmly attached to thewall structure just above the door opening. Track 14 is supported alongits length by struts 40 and 42 which are securely attached to the roofrafters. Bearing 28a is bolted to the right end of a bracket 44, theleft end of which is'bolted to the wall structure above the dooropening.

Door can be seen in section in FIG. 3. Top section 10a is substantiallythicker than bottom section 1012 and as shown has a generally curvedouter surface. Curving the outer surface stresses it and increases thestructural strength of the door which is especially desirable when thedoor is in the elevated generally horizontal position. The upper portion10a of door 10 is stiffene'd by a set of horizontal trusses or members100 which are glued or otherwise fastened between the inner and outersurfaces.

The top portion of door 10 overhangs the bottom portion by a substantialamount and because of this, drip-off from the top section 10a is wellaway from the bottom edge of bottom section 10b. As shown in FIG. 3, thetop of bottom-section 1019 has a flange 10b for bolting to the bottom oftop section 10a. The top and bottom sections are bolted or otherwisejoined along a joint 46. Relatively small doors are bolted together andtransported as one piece. If a door is relatively large it istransported in two sections and assembled at the site. Access holes 48along the lower edge of the top section of door 10 facilitate boltingtogether the top and bottom sections of the door. Bearing 17b is held inplace with a clamping arrangement 19. The outer covering of door 10 maybe of wood, metal, or fiberglass. It can be seen in FIG. 3 that theupper portion of side track 20b slopes inwardly, the lower portion issubstantially vertical. Referring to FIG. 5, track 20a is welded on orotherwise securely attached to an angle iron 60 which is bolted to thewall. A closure strip 62 is securely fastened to the wall and extends ina vertical direction. Closure strip 62 covers or seals the gap betweenthe lower door sectionand the wall. Referring briefly to FIG. 3 aclosure strip 64 is securely fastened to the upper portion 100 of thedoor and seals the gap between the upper door section and the wall.

In operation rope 36 is pulled downward to open the door. This causespulley 38 which is mounted on shaft 36 to turn. As shaft 36 turns,pulleys a and 30b and pulleys 24a and 24b turn..As pulleys 30a and 30bturn, counterweights 34a and 34!) are lowered. Cable drums 24a and 24bbegin taking up cables 22a and 22b. Door 10 begins moving upward andbegins rotating about pivots 16a and 16b, which are also moving upward.During the first few inches of travel. the rollers 12a and 12b travelnearly vertically in tracks 14a and 14b. Pivots 16a and 16b begin movingupwardly and inwardly along the upper portions of side tracks 20a and20b. As the door continues to open, the pivots travel upward and inwardin the side tracks and the rollers move first upward and then downwardin the overhead tracks. Referring briefly to FIG. 2, the door 10 isshown in the half open and fully open positions by the dashed or phantomoutlines. The overhead tracks 14a and 14b are bowed as shown toaccommodate th relatively thick I upper portion of the door. It is seenthat in order for the door to eventually reach a horizontal position,the upper edge of the door must eventually travel downward. This it doesduring its travel in the inner portion of the tracks 14a and 1412.

FIG. 8 shows another embodiment of door 10 in which the upper portion10a is triangular-shaped in cross-section instead of having a curved,stressed outer surface. This embodiment can be used if less structuralstrength is required.

A single preferred embodiment of the invention has been shown.Modifications to this embodiment and other equivalent embodiments may bedevised by those skilled in the art without departing from the spiritand scope of the invention. Therefore the invention is to be limitedonly by the following claims.

what is claimed is:

1. An improved overhead door assembly for retarding the buildup of snowand rain at its base when closed and stowable in a compact manner whenopened, comprising:

a. a door having top and bottom portions and a generally planar innersurface, said bottom portion being of generally constant thickness andsaid top portion being generally thicker than said bottom portion toform a discontinuity in the door outer surface and to provide anoverhang across the entire door width which shelters the door base fromthe accumulation of snow and rain;

b. a pair of low-shaped overhead tracks for mounting inside and over adoor opening, each of said tracks bowing downwardly and having a frontportion nearest the door opening which slopes upward and away from thedoor opening, and a rear end portion furthest removed from the dooropening which slopes downward and away from the door opening, saidtracks accommodating said door in a stable generally horizontal overheadopen position;

c. means attached to the top of said door for traveling in said overheadtracks as the door is opened and closed; a pair of side tracks formounting at the sides of the door opening, each of said side trackshaving a generally vertical bottom portion and a top portion whichslopes upwardly and away from said bottom portion to slidably guide saiddoor to a generally horizontal overhead open position;

e. means for pivoting said door about a transverse axis. said pivotingmeans traveling in the side tracks;

f. means for counter balancing said door to ease its movement from theopen to the closed position.

2. The improved door assembly of claim 1 wherein said door top portionincludes an outer surface which is curved to provide a stressed shellstructure for increased compression strength.

3. The improved door assembly of claim 1 wherein the top portion of saiddoor is generally triangularshaped in cross-section.

1. An improved overhead door assembly for retarding the buildup of snowand rain at its base when closed and stowable in a compact manner whenopened, comprising: a. a door having top and bottom portions and agenerally planar inner surface, said bottom portion being of generallyconstant thickness and said top portion being generally thicker thansaid bottom portion to form a discontinuity in the door outer surfaceand to provide an overhang across the entire door width which sheltersthe door base from the accumulation of snow and rain; b. a pair oflow-shaped overhead tracks for mounting inside and over a door opening,each of said tracks bowing downwardly and having a front portion nearestthe door opening which slopes upward and away from the door opening, anda rear end portion furthest removed from the door opening which slopesdownward and away from the door opening, said tracks accommodating saiddoor in a stable generally horizontal overhead open position; c. meansattached to the top of said door for traveling in said overhead tracksas the door is opened and closed; d. a pair of side tracks for mountingat the sides of the door opening, each of said side tracks having agenerally vertical bottom portion and a top portion which slopesupwardly and away from said bottom portion to slidably guide said doorto a generally horizontal overhead open position; e. means for pivotingsaid door about a transverse axis, said pivoting means traveling in theside tracks; f. means for counter balancing said door to ease itsmovement from the open to the closed position.
 2. The improved doorassembly of claim 1 wherein said door top portion includes an outersurface which is curved to provide a stressed shell structure forincreased compression strength.
 3. The improved door assembly of claim 1wherein the top portion of said door is generally triangular-shaped incross-section.